Polyvinyl acetal resin sheets containing di-(2-(beta -ethoxyethoxy)-ethyl-) formal



Patented Dec. 1939 4 PATENT orrlcs- POLYVINYL AOETAL RESIN SHEETS CON- TAINING DI (2 (F EfIlIOXYETIIOXYF ETHYlr) F Henry B. Sillfli, Rochester, N. Y., "timer to Eastman Kodak Company. Rochester c rporation of New Jersey No 1mm. Application December :2, 1m,

Serial No. 181,222 Y 4 (cl. zoo-as) This invention relates to plastic compositions, and more particularly to compositions comprising a polyvinyl acetal resin and a conditioningagent.

Oneobject of this invention is to product com- -5 positions of matter which may be made into per-' manently transparent, strong and flexible sheets i or films of desired thinness which are-substam' tially waterproof, are unaffected by ordinary photographic fluids and possess the desired properties of a support for sensitive photographic I coatings. Another object of my invention is to produce compositions of matter which can be -made into sheets suitable for .use in laminated. shatter-proof glass. Still another'obiect: is to 16 produce compositions which can be rolled, extruded, molded or otherwise-worked into relatively thick sheets and massive plastics. A further object is to produce compositions suitable for use in lacquers, artificial silk filaments, wrap- 20 ping tissues and the like. Other objects will hereinafter appear. J

I have discovered that di-(2-(p-ethoxyethoxy) -ethyl-) formal is every conditioning agent for certain of the polyvinyl acetal' resins, namely, the polyvinylacetal in which a predominating proportion of the acetal groups are acetaldehyde acetal groups or butyraldehyde acetal groups. Not only does it serve as a plasticizer in the accepted of the term, increasing the flexibility and toughness of polyvinyl acetaldehyde or 'butyraldehyde metal when the tension is released. This property renders such sheets, which I shall call rubbery" sheets, particularly useful in the manufacture of shatter-proof glass. I

Di-'(2-(p-ethoxyethoxy) -ethyl-) formal the structural formula and can be prepared as follows:

600 g. of calcium chloride is dissolvedin 13503.

(10 gram-moles) of diethylene glycol monoethyl oeaememenecn.

ether by heating to about 180 C. with stirring. The solution is cooled to about 100 C., and'300 3. (l0 'gram moles of 01120) of trloxymethylene is added and well mixed in. The mixture is heated k'radually with frequent shaking until refluxing 6 starts. This occurs at about l40-145 C. Refluxing is continued for about 3 hours. The mixture is then allowed to cool to room temperature, and the top layer is decanted and distilled. The materla l'coming over below l C. at normal 10 pressure is discarded. The residue is distilled under reduced pressure, the material coming over below165" C. at 7 mm. pressure being discarded.

The di-(Z-(p-ethoxyethoxy)-ethyl formal distills at 165-235" C. at '7 mm. pressure. 15

For the manufacture of cast films or sheets, the polyvinyl acetal resin and di-(Z-(p-ethoxyethox'yl-ethyb) formal may be diwolved in a suitable solvent or solvent mixture, such, for instance, as acetone, methanol, acetone-methanol 2o mixtures. ethylene chloride-methanol mixtures, etc., about 300 to 500 or more parts of the solvent orsolvent mixture being used per parts of the resin. From about 2 to 100 parts or more of di-(Z-(p-etholzyethoxy)-ethyl-) formal per 100 25 parts of resin may be employed, depending'upon the nature of the resin and the purpose for which the sheets are to be used. Suitable proportions of di- (2-' (,s-ethoxyethoxy) -ethyl-) formal for any resin and 81111311112088 may be readily de- 30 termined by experiment. For the manufacture of sheets suitablefor photographic film base, from 2to 25 parts of di-(2-(p-ethoxyethoxy)- ethyl-) formal per 100 parts of resin are suitable.

The resin solution is cast as a sheet, the solvent 36 evaporated, and the sheet stripped from the surface. 7

Sheets for use in laminated glass may be formed by casting, or may be made without the use of volatile solvent by extrusion, for example in the manner set forth in application Serial No. 147,934 of John S. Kimble and Ernest C. Blackard, filed June 12, 1937. For instance, 40 or more parts of di-(2-(fl-ethoxyetholry) -ethyl-) formal and 100 parts of a polyvinyl acetaldeuntil complete homogenization has taken place.

The polyvinyl acetal resins can be prepared by so polyvinyl alcohoijwith an aldehyde mthe presence of an aeetal condensation catalyst,- e. g.amineral acid. Theseresinscanalsobeprepared by simultaneously de-esterifying a poly- 3 vinyl aliphatic ester and reacting the de-esterk. flcation product with an aldehyde in the presence of a de-esterifying catalyst and acetal condensap lyvinyl butyraldehyde acetaldehyde mixed acetal resins.

Examples of the preparation of polyvinyl acetaldehyde acetal resins may be folmd in U. 8.

,Patent 2,044,730,.Example; 1:11. 8. Patent 1,955,-

068, Example 2; U. a. Patent 2,036,092, Examples '4, 5 and 6; British Patent 468,598, Examples 1, 2, 3, 4 and 7; British Patent 404.279, Examples 1,

2, 4, 5, 6, 'I and 8; U. S. Patent'1,9 90,399; and

' butyraldehyde acetaldehyde ,mixedacetal resin.

French Patent 808,578." Examples 1, 2 and 3.

Additional examples of the preparation of polyvinyl acetaldehyde acetal resins are as follows:

. 100 lbs. of polyvinyl acetate, the viscosity of whose molar solution in benzene was 45 centipoises, was dissolved in 300 lbs. of 95% ethyl alcohol. To this solution-were added 30 lbs. of paraldehyde and 25 lbs. of 35% H0]. The reaction mixture was allowed to stand for 41days at C., after which it was diluted'with ethyl alcohol, and the resin precipitated by pouring into cold water, washed -and dried. Analysis showed the resin to have an acetate group content equivalent to 2.1% by weight of polyvinyl acetate and a hydroxyl group content equivalent to 12.9% by weight of. polyvinyl alcohol. 25 lbs. of polyvinyl acetate, the viscosity of whosemolar solution in benzene was 45 centi-. poises, was dissolved in '15 lbs. of 95% ethyl alcohol. Tothis solution was added} lbs. of paraldehyde and a solution of 3 lbs. 12 om. of sulfuric acid in 3 lbs. 12 of 95% ethyl alcohol. The

reaction mixture was'allowed to stand for 'lidays at 40 0., after which it was diluted with ethyl alcohol, and the resin precipitated by pouring into cold water,.washed, and dried. Analysis V acetate and a hydronl group content equivalent showedjthe resin to have'an acetate group con-- tent equivalent to 1.7% by weight of polyvinylto 13.8% by weight of polyvinyl alcohol. 7 Examples of the preparation of polvvinyl butyraldehyde ac'etal resins may be folmd in-U. 8. I

Patent 2,044,730, Examples 2, Kind 6; ale-a Patent 466,598,- Example 303,-Example 1; French Patent 818,514, Exam- 5; French Patent 81's,

pics 1, 2, 3 and 4; and British Patent459,8'78,

Examples 1, 2, 5, 6, '1, -8, 9 and 10.

An additional example of thep'reparatlon of a polyvinyl butyraldehyde acetal resin is as follows: 23.6 lbs. of polyvinyl acetate, the viscosity of whose molar solution in benzene was 45 centipoises, was dissolved in 56.5 lbs. or ethylalcohol. ,To this solution was added 7.9 lbs. of

butyraldehyde and 5.9 lbs. of 35% HCl. The reaction mixture was allowed to stand for 4 days tated by-pouring into cold water. washed. and

dried. Analysis showed the resin to have an acetate group content equivalent \to 8.1% by weight of polyvinyl acetate and a hydroxyl group content equivalent to 16.3% by weight of polyvinyl alcohol.

An example of the preparation of a polyvinyl is given inFrench Patent 813,303, Example 2.

What I claim as my invention and desire to be selected from the group consisting of acetaldehyde acetalgroups and butyraldehyde acetal groups, and at least 40 parts, approximately, of di-(z-(p-ethoxyethoxy) ethyl formal as an elasticizer therefor.

2. A transparent, rubbery sheet comprising parts of apolyvinyl acetaldehyde acetal resin and at least 40 parts, approximately, of di-(2- ticizer therefor.

4. A transparent,-rubbery sheet comprising a polyvinyl acetal resin in which a predominating the' group consisting of acetaldehyde acetal groups and butyraldehyde acetal groups, and an amount of di-(2-(p-ethoxyethoxy)-ethyl-) formal suiii'cient to impart to the sheet a rubbery character withoutsubstantially impairing its transparency.

. HENRY B. SMITH.

.at 40 C.',a.fter which it was diluted with ethyl alcohol and acetic acid, and the resin preoipi-- 5 (p-ethoxyethoxwI-ethyb) formal as an. elasproportion of the acetal groups are selected from I 

